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Opuntia Diploursina
''Opuntia diploursina'' is a species in the family Cactaceae, that grows near and in Lake Mead National Recreation Area and northward across Nevada's Mormon Mesa, into Utah. This species is a close relative and probable ancestor of ''Opuntia erinacea'', but "...differs in minor spines more closely appressed to pad surface, spines smaller in diameter and more flexible, inter-areolar distance less, upright growth habit, larger fruit with longer, more flexible spines, larger seeds, and diploid chromosome number (2n=22)". ''Opuntia diploursina'' is also related to another diploid species, ''O. trichophora'', but differs from that species, as stated in the original description, in more upright growth habit, more minor spines that are more closely appressed to pad surface, closer spaced areoles, often yellow spine color as opposed to white or gray mature spines;; more and longer spines on fruit. ''O. diploursina'' also has curling major spines, and larger fruit. The two species are sep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cactaceae
A cactus (, or less commonly, cactus) is a member of the plant family Cactaceae, a family comprising about 127 genera with some 1750 known species of the order Caryophyllales. The word ''cactus'' derives, through Latin, from the Ancient Greek word (''káktos''), a name originally used by Theophrastus for a spiny plant whose identity is now not certain. Cacti occur in a wide range of shapes and sizes. Although some species live in quite humid environments, most cacti live in habitats subject to at least some drought. Many live in extremely dry environments, even being found in the Atacama Desert, one of the driest places on Earth. Because of this, cacti show many adaptations to conserve water. For example, almost all cacti are succulents, meaning they have thickened, fleshy parts adapted to store water. Unlike many other succulents, the stem is the only part of most cacti where this vital process takes place. Most species of cacti have lost true leaves, retaining only Thorns, s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Mead National Recreation Area
Lake Mead National Recreation Area is a U.S. national recreation area in southeastern Nevada and northwestern Arizona. Operated by the National Park Service, Lake Mead NRA follows the Colorado River corridor from the westernmost boundary of Grand Canyon National Park to just north of the cities of Laughlin, Nevada and Bullhead City, Arizona. It includes all of the eponymous Lake Mead as well as the smaller Lake Mohave – reservoirs on the river created by Hoover Dam and Davis Dam, respectively – and the surrounding desert terrain and wilderness. Formation of Lake Mead began in 1935, less than a year before Hoover Dam was completed. The area surrounding Lake Mead was protected a bird refuge in 1933, later established as the Boulder Dam Recreation Area in 1936 and the name was changed to Lake Mead National Recreation Area in 1947. In 1964, the area was expanded to include Lake Mohave and its surrounding area and became the first National Recreation Area to be designated as such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hybrid Swarm
A hybrid swarm is a population of hybrids that has survived beyond the initial hybrid generation, with interbreeding between hybrid individuals and backcrossing with its parent types. Such population are highly variable, with the genetic and phenotypic characteristics of individuals ranging widely between the two parent types. Hybrid swarms thus blur the boundary between the parent taxa. Precise definitions of which populations can be classified as hybrid swarms vary, with some specifying simply that all members of a population should be hybrids, while others differ in whether all members should have the same or different levels of hybridization. Hybrid swarms occur when the hybrid is viable and at least as vigorous as its parent types; and there are no barriers to crossbreeding between the hybrid and parent types. Swarms cannot occur if one of these conditions is not met: if the hybrid type has low viability, the hybrid population cannot maintain itself except by further hybrid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyploid
Polyploidy is a condition in which the cells of an organism have more than one pair of ( homologous) chromosomes. Most species whose cells have nuclei ( eukaryotes) are diploid, meaning they have two sets of chromosomes, where each set contains one or more chromosomes and comes from each of two parents, resulting in pairs of homologous chromosomes between sets. However, some organisms are polyploid. Polyploidy is especially common in plants. Most eukaryotes have diploid somatic cells, but produce haploid gametes (eggs and sperm) by meiosis. A monoploid has only one set of chromosomes, and the term is usually only applied to cells or organisms that are normally diploid. Males of bees and other Hymenoptera, for example, are monoploid. Unlike animals, plants and multicellular algae have life cycles with two alternating multicellular generations. The gametophyte generation is haploid, and produces gametes by mitosis, the sporophyte generation is diploid and produces spores by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Opuntia
''Opuntia'', commonly called prickly pear or pear cactus, is a genus of flowering plants in the cactus family Cactaceae. Prickly pears are also known as ''tuna'' (fruit), ''sabra'', ''nopal'' (paddle, plural ''nopales'') from the Nahuatl word for the pads, or nostle, from the Nahuatl word for the fruit; or paddle cactus. The genus is named for the Ancient Greek city of Opus, where, according to Theophrastus, an edible plant grew and could be propagated by rooting its leaves. The most common culinary species is the Indian fig opuntia (''O. ficus-indica''). Description ''O. ficus-indica'' is a large, trunk-forming, segmented cactus that may grow to with a crown of over in diameter and a trunk diameter of . Cladodes (large pads) are green to blue-green, bearing few spines up to or may be spineless. Prickly pears typically grow with flat, rounded cladodes (also called platyclades) containing large, smooth, fixed spines and small, hairlike prickles called glochids that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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